Disease defence starts with seed testing

Direct seeding, shorter crop rotations, earlier seeding — they’re all management practices that have the potential to help growers harvest higher yielding, more profitable cereal and pulse crops. But each practice comes with some level of risk.The first step in defending your crop against these challenges is to take a good look at the seed.

​​For example, soil moisture management (i.e. keeping crop residue from the previous crop) and choosing to direct seed saves time, but soils are cooler and insects and soil-borne diseases overwintering on crop residue can prove challenging. In addition, shorter rotations allow growers to more often plant crops that deliver higher returns, however, profit potential may be significantly reduced by higher levels of disease and pests.

The first step in defending your crop against these challenges is to take a good look at the seed, says Ted Labun, Seedcare Technical Lead for Syngenta in Western Canada. “When you’re trying to get a crop off to a good start you need to avoid seed that may be compromised due to frost or mechanical damage or even infection by seed-borne diseases. That’s why seed testing is so important – it sets the stage for potential yield and return on investment.”

Testing for germ, vigour and disease

After harvest and prior to cleaning seed, Labun recommends setting aside some seed for testing at an accredited seed laboratory. (A list of accredited seed labs is available from the Canadian Seed Institute.) Start with a germination and vigour test. Germination results will help to determine seeding rates and optimize stand establishment. We want to be confident the seed lot chosen will come out of the ground strong.

The lab can also conduct fungal diagnostics to identify potential seed-borne pathogens and estimate the percentage of seed that is affected by specific diseases. Detecting disease at this stage allows you to make informed decisions about seed lots and select the appropriate seed treatment to manage disease.

Fall weather and harvest conditions will play a key role in determining seed quality and disease levels. Excessive moisture and high humidity can be a recipe for in-crop disease pressure, which leads to high levels of seed-borne disease, lower germination rates and poorer vigour.

Seed and soil-borne diseases

With a disease like seed-borne Fusarium, we want to plant seed that has low levels of infection to start with, if at all possible. For seed infections, seed treatment plays an important role to prevent seed rot or seedling blight as the seeds begin to germinate after planting. Since Fusarium spp. can also be soil-borne, causing damping-off or root rot, seed treatments will also minimize the impact on the crop and maintain a healthy seedling.

It’s also important to understand soil-borne disease challenges when assessing seed. For example, if a farm has a history of Pythium spp. or Rhizoctonia spp., this should also be considered when assessing seed quality and seed treatment needs.

“The success of a crop largely depends on the seed you put in the ground,” Labun says. “Knowing the quality of that seed will help determine what other investments are required to reach your yield goals.”

For more information about seed testing or seed treatment, contact our Customer Interaction Centre at 1-87-SYNGENTA (1-877-964-3682).